From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:57324 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932105AbeDVOQO (ORCPT ); Sun, 22 Apr 2018 10:16:14 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Richard Weinberger , Boris Brezillon , Artem Bityutskiy Subject: [PATCH 4.4 25/97] ubi: Reject MLC NAND Date: Sun, 22 Apr 2018 15:53:03 +0200 Message-Id: <20180422135306.451761209@linuxfoundation.org> In-Reply-To: <20180422135304.577223025@linuxfoundation.org> References: <20180422135304.577223025@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Richard Weinberger commit b5094b7f135be34630e3ea8a98fa215715d0f29d upstream. While UBI and UBIFS seem to work at first sight with MLC NAND, you will most likely lose all your data upon a power-cut or due to read/write disturb. In order to protect users from bad surprises, refuse to attach to MLC NAND. Cc: stable@vger.kernel.org Signed-off-by: Richard Weinberger Acked-by: Boris Brezillon Acked-by: Artem Bityutskiy Signed-off-by: Greg Kroah-Hartman --- drivers/mtd/ubi/build.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -889,6 +889,17 @@ int ubi_attach_mtd_dev(struct mtd_info * return -EINVAL; } + /* + * Both UBI and UBIFS have been designed for SLC NAND and NOR flashes. + * MLC NAND is different and needs special care, otherwise UBI or UBIFS + * will die soon and you will lose all your data. + */ + if (mtd->type == MTD_MLCNANDFLASH) { + pr_err("ubi: refuse attaching mtd%d - MLC NAND is not supported\n", + mtd->index); + return -EINVAL; + } + if (ubi_num == UBI_DEV_NUM_AUTO) { /* Search for an empty slot in the @ubi_devices array */ for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)